Described below I a method for determining the location of a mobile device within a building, in which the mobile device receives position information from room devices.
Local beacons that are installed in rooms and that transmit an ID for a room, for example RFID tags, small Bluetooth or infrared transmitters, QR codes or the like are known. In all these cases, this requires a mobile device to have a reading or reception unit in order to identify these local beacons, however.
In addition, terminal-based radio positioning, e.g. by Wi-Fi, is known. For this, the mobile device has a map containing field strengths and positions of radio transmitters, e.g. Wi-Fi access points, and it then uses currently measured field strengths to compute a probable position. This method is highly computation intensive, however, and requires field strength maps that are as up to date as possible.
Likewise based on the same technology but more widespread is server-based radio positioning, also by Wi-Fi, for example. In this case, the positioning computation is performed by a server, however, which is problematic for the privacy of the user of the mobile device.
A further known method on mobile devices uses compasses, inertial sensors and gyroscopes in order to record the movement and orientation of the mobile device and to compute a position therefrom.
This method is usually too imprecise when taken on its own and is therefore often combined with other methods.